Looking for software/hardware package to control Solenoids/Actuators

[JustinM]

All,
I am looking for a commercial off the shelf package for controlling solenoids that are hooked to pneumatic cylinders for doing actuation cycles. Are there any off the shelf packages out there? I have looked, but not had much luck.

I am trying to set up a life cycle test of opening and closing a latch. I will be using a Parker linear actuator cylinder with pneumatic valves that are actuated via solenoids. I need the PC to send a signal to the solenoid at the correct rate and cycle up to 8 channels. Any ideas?

Thanks,
Justin

 

[jraef]

Solenoids are tough duty cycle for switching devices; they have a nasty habit of inductive kickback that burns contacts or fries SSRs. The best approach is to use an I/O card that uses replaceable relays as the switches, or use an external I/O unit that you can talk to with your PC via serial port.


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[itsmoked]

It would be a good application for DC solenoids and proper freewheeling diodes. You could use a typical OPTO-22 style 8 channel board and run it with a printer port and a separate unregulated power supply on the optically isolated solenoid side.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ScottyUK]

A solenoid shouldn't be a tough load for any relay with a freewheel diode (DC) or a MOV (AC), but considering the cost of a DIN-rail mounting relay compared with the cost of an I/O card I'd put the extra relay between the solenoid and the PC. The PC output driving the relays could be either solid state or small pilot relays.




----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[MikeHalloran]

<shaggy dog story>
I had a friend who designed and produced the software and hardware for your application.

The software looked sort of like a spreadsheet, with time intervals in rows, and solenoids or motors or whatever in columns. So basically you decided on a time interval, and put an X wherever you wanted an output bit 'on', and the software stepped down rows at the rate you wanted and did what you told it to. It could loop on condition and do some other logical gymnastics, too.

The software talked over a single serial port to a bunch of modular controllers, for stepper motors, arrays of solenoids, etc., using multidrop RS-232. (Yes, I know you can't do that. He didn't know it was impossible, so he did it. Up to 32 addresses.)

Then he died.
</shaggy dog story>

Look at this page:

http://www.empi-fl.com/products_projects.html

See the entry for the former Computer Control Corporation, which produced the modules.
Maybe they've got enough stuff lying around to piece together a small system.



Mike Halloran
Pembroke Pines, FL, USA

 

[tygerdawg]

seems like it would be so easy with a cheapo PLC with relay outputs...why do you need to use the PC?

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[BillPSU]

You can setup mechanically actuated valves to do the cycling to cycle the testing station. There is no need for a plc or electrical hardware to do this task. Add a mechanical counter and check the testing over time.

 

[jimarsh]

I agree with tygerdawg. A cheap plc with a very simple program, and a solid state 12-24vdc relay would be the simplest way to do this. In the program you could put a counter which you could have it tied to an output(led) that would indicate a certain number of cycles completed.

 

[JustinM]

Could I use a "Smart Relay" to do this?

http://www.us.telemecanique.com/products/Machine_Control/Relays_Timers/Logic_Relay/index.html

The consensus here is that I don't need a PC to do the job, however it will be complicated getting 4 relays to fire at the right time. I am looking into PLC's as well.

Thanks for all your help...

Justin

 

[itsmoked]

Absolutely!. I'd do it that way.

For counting you could use an internal non-volatile register if the Zelio has it. Or use an external electromechanical counter. You don't want a power failure to cause a loss of the count of test cycles that have passed.

Keith Cress
kcress -

http://www.flaminsystems.com